Let-off mechanism foe looms



Y(No Model.)

2 Sheets-Sheet 1.

G. PARK. LET-OFP MEGHANISM POR LooMs.

No. 431.707. f Patented Ju`1'y 8, 1890.y

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(No Model.) 2 sheetssheen 2. G. PARK. ALlEIT-OFP MBGHANISM POB. LOOMS-l No. 431,707. Patented July 8, 1890.

JM/vanto@ @Will/zoom GILBERT PARK zie/? UNITED .STATES l PATENT OFFICE.

i GILBERT PARK, OF SPENCER, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO JOHN G. AVERY, OF SAME PLACE.

LET-OFF MECHANISIVI FOR LOOMS.

SPECIFICATION forming part of Letters Patent No. 431,707, dated July 8, 1890.

Application filed September 10, 1889. Serial No. 323,549. (No model.)

To aZZ whom it may concern:

Be it known that I, GILBERT PARK, a citizen of the United States, and a resident of Spencer, in the State of Massachusetts, have invented a new and useful Improvement in Let-OE Mechanism for Looms, of which the following is a speciiication.

This invention consists of certain novel colnbinations of parts, hereinafter set forth and claimed, designed for application to the different makes of power-looms now commonly used and to looms constructed on the `same general principle, in which the warp beam is or may be positively turned a greater or less distance to let o the warp for one pick at each half-turn of the main shaft by means of a cam on the latter, through the.

medium of suitable pawl-and-ratchet converting mechanism and Worm-gearing The objects of the present invention are, rst, to automatically and positively increase the movement of the warp-beam in proper proportion as its diameter decreases by means of a screw-actuated back-stop and without the contact of any part of the mechanism with the warp itself; secondly, to provide for regulating the number of picks for different sizes of yarn with such screw mechanism; thirdly, to facilitate resetting the mechanism when a fresh warp-beam is put in the loom; fourthly, to prevent overmovements of heavy warpbeams by inertia; and, iifthly, to pro-- vide for operating in the most direct manner the positively-actin g automatic grip or gripping device, by which such overmovements are prevented.

Two sheets of drawings accompany this specification as part thereof.

Figure I of the drawings represents a ver-l tical cross-section through the frame warpbeam spindle and main shaft of a loom, showing its let-off mechanism in elevation. Fig. 2 represents a sectional view of the parts of the latter at and below the plane indicated by the line 2 2, Fig. l. Fig. 3 is a fragment-A ary perspective view showing the automatic grip and a supplemental device for preventing overmovements of the warp-beam. Fig. 4 is a fragmentary perspective view showing the screw-actuated back-stop and its appurtenances. Fig. 5 is a like view showing a modification of the screw mechanism,'and Fig. 6 is another like view showing a modification of the automatic grip.

Like letters of reference indicate corre- 55 spending parts in the several figures.

For the purposes of this invention the re. quired slow intermittent motion may be imparted to the spindle A of the Warp-beam by the rotary main shaft B, through the medium 6o of any suitable cam O on the latter, and any approved pawl-and-ratchet or like converting mechanism and any suitable worm-gearing. I prefer an oval cam fast on the shaft and projecting equally on opposite sides thereof, 6 5

as shown in Figs. l and 4, and the converting mechanism and worm-gearing represented in Figs. l and 2. Such converting mechanism comprises a lever D, which works on a pivot E, supported by the end frame of the 7o loom adjacent to which the caln O is located. Said lever is connected bya link F with an oscillating dog-holder G, whose dogs H mesh with a crown ratchet-wheel I, fast on a vertical ratchet-shaft J, and the latter carries the customary screw or worm Kin mesh, when in operation, with a worm-wheel L, fast on the warp-beam spindle A. The cam C is preferably set on the shaft B so that it lets off when the lay is going back. Thus when the lay 8o nal slots, as shown in Figs. l, 2, and 4L, so as 85 to provide for varying the distance between its pivot E, which is conveniently ixed, and its terminal contact-piece which is engaged by the cam. Finer adjustments to determine the number of picks with greater nicety are 9o provided for at the top of the lever. The dogs I-I are preferably four in number, and each of the last three is an eighth of an inch shorter than the preceding dog, so that one will alwaysbite one of the crown-teeth of the ratchet-wheel. The number of dogs may be increased for finer work, and the yvariation in their length reduced to one-sixteenth of an inch. The dogs are held down to their work by springs. A dog-lifter V,- in the form 10o of a slotted disk with a radial arm over each dog, is held down upon the dog-carrier Gr, and

its independent motion is limited by screwsof the dog-lifter, and by turning the latterindependently of the dog-carrier the dogs are simultaneously lifted clear of the ratchetteeth, so as to free the ratchet-shaft when a fresh warp-beam is being attached, or in case of pick-outs. A hand-rod W provides for turning the dog-lifter from the front of the loom in case of pick-outs; and, in addition to a hand-wheel X, faston the ratchet-shaft at its upper end, it is provided with afast gearwheel Y, meshed by a pinion Y2, which is carried by the rear end of a horizontal shaft Z, the front end of which is furnished with a hand-wheel X2 to provide for readily turning the ratchet-shaft from in front of the loom in case of pick-outs.

The above converting mechanism and wormgearing are more fully described and are shown more in detail and referred to for the most part with like reference-letters in the specification and drawings forming part of a previous application for patent filed by me July 23, 1889, Serial No. 318,373, in favor of which all patentable features thereof are hereby disclaimed. To gradually increase the action of said converting mechanism and worm-gearing in due proportion to the def creasing diameter of the warp-beam M, l provide the warp-beam spindle A with a worm N, rigidly fastened thereon, and transmit motion therefrom through the medium of a small worm-gear O, al screw P, a nut Q or Q2, and preferably a peculiarly-slotted lever R, to a back-stop S, which coacts with a reciprocating or oscillating part of said converting mechanism, and preferablywith a shoulders l ofthe yoke portion which carries the contactpiece of said lever D immediately adjacent to the cam C, so as to limit the retraction and consequently the succeeding throw of said part, and thus to limit each effective movement of the dogs H and the consequent fractional turn of the ratchet-Wheel I, shaft J, and -worm K and that of the worm-wheel L, spindle A, and warp-beam M in a direct and positive manner without touching the warp itself. Said worm-gear O is fast on the screw P between a pair of bearings at the extremity of a bracket T, which is attached to the adjacent end frame of the loom by apivotal stem p, Fig. 4, in line with the horizontal diameter ofthe gear, and so located that the worm N meshes properly therewith when the spindle A drops into its open bearings, as indicated in Figs. l and 4. The screw P and said wormgearing, through which it is actuated, are proportioned to the warp-beams and warp which are to be used in the loom. WVith a warpbeam carrying six hundred turns of warp .I use a worm of four and a half threads to the inch and a forty-tooth gear on the screw, the

latter being cut ten threads to the; inch, and the nut Q or Q2, which is fitted to said screw, is consequently moved one and a half inches during the emptying of a beam. The nut Q or Q2 has a pivotal stem q, which passes through a longitudinal slot ain said lever R,

and by fastening the nut higher or lower in said slot a the graduating mechanism is adjusted for different sizes of yarn. With coarser yarn the nut is raised. With finer yarn it is lowered.

`The nut Q (shown in Figs. l, 2, and 4) is divided diametrically and provided with a clamp-screw c, Fig. 4, so that it may be released from the screwP and reclamped therel on at the starting-point to facilitate resetting the back-stop S When'a new warp-beam is put in the loom. A one-partnutmaybe used instead, as shown at Q2 in Fig. 5 and be. run back by turning the gear Oby hand after the empty warp-beam is removed from the loom.

The lever R is conveniently supported by a fiXed pivot E2 at its upper end, the same being attached to the adjacent end frame of the loom, and this lever carries the back-stop S at its opposite end, being provided with a slot y b, within which the back-stop is adjustable toward or away from said surface s, with which it coacts, so that the lever may hang as nearly vertical as is practicable with the back-stop at the proper distance from said" coacting surface at the beginning of the operation.

The partsof the converting mechanism are shown as they appear at the end of an effective stroke, and the said nut Q, lever R, and back-stop S of the graduating mechanism are shown as they appear when the warp-beam is full, and the dotted lines in Fig. 1 represent the movement of these -parts by the warpbeam spindle A through the medium of the worm N, worm-wheel O, and screw P.

To prevent overmovements of heavy warpbeams by inertia, an automatic grip is preferably added to the said converting mechanism, as follows, (see Figs. l, 3, and 6:) Apair of short levers U U2 are hinged together at one end and form, adjacent to their hinge h, Figs. 3 and 6, concave jaws, which are provided with linings j, Figs. 3 and 6, of leather or the like to coact with the ratchet-shaft J, which is embraced by said jaws at a convenient point. The other end of the jaw-lever U is attached by a vertical pivot p to a bracket U3, which is affixed to said adjacent end frame of the loom, and the corresponding end of the jaw-lever U2 carries avcontact-piece U4 or U5, the free end of whichcoacts with the opposing edge of the lever D of the converting mechanism as the latter approaches the invariable limit of its eective movements. grip of the jaws upon the shaft when so closed, the contact-piece U4 or U5 is adjusted To vary the loo IIO

above the pivot E of said lever D, as shown in Figs. 1 and 3, or below said pivot and below the worm I, as shown in Fig. G. In the latter arrangement the jaw-levers U U2 are reversed. Said j aw-lever U is pivoted to the lower bearing J of the shaft J, and the contact-piece U5 is adapted, by a rebent outer end f, to coact with the far or front edge of the lever D.

As a supplemental or alternative device for preventing overmovements of the warpbeam, I .employ a spiral drag-springV, Figs. l and 3, surrounding the ratchet-shaft J. The same is coiled in a direction opposite that of the ordinary rotation of the shaft, and is conveniently compressed, more or less, as required, between the upper bearing J 2 of said shaft and an opposing collar V2, which is adjustably fastened on the shaft by a screw g.

Details whichhave not been specified may be of any approved description, and other like modifications will suggest themselves to those skilled in the art.

Having thus described the said let-off for looms, I claim as my invention and desire to patent under this specificationl. The combination, with the warp-beam, the warp-beam spindle, and a reciprocating part and connections which turn said beam and spindle, of a worm carried by said spindle, a worm-gear driven by said worm, a screwl and nut transmitting motion from said gear, and a movable back-stop which coacts with said reciprocating part and is retracted through the medium of said screw and nut at each movement ot' the warp-beam, said worm, worm-gear, screw, and nut being proportioned to the number of turns of warp on the warp-beam, so that the escape of a given length of warp is accompanied bya proportionate retraction of the back-stop, substan tially as hereinbefore specified.

2. The combination, with the warp-beam spindle, worm-gearing transmitting motion therefrom, a screw turned by said gearing, and a nut iitted to said screw, of alever having a pivot at one end, provided at its other end with a back-stop, and provided intermediately with means vfor attaching said nut thereto and adj ustingthe same toward or away from said pivot, substantially as hereinbefo're specified.

3. In combination with the warp-beam spindle, worm-gearing transmitting motion therefrom, a screw turned by said gearing, and a back-stop actuated by said screw, an interposed nut fitted to said screw, divided diametrically and provided with a clamp-screw, substantially as hereinbefore specified.

4. The combination of a rotary let-off cam, a pawl-and-ratchet converting mechanism actu ated by said cam, a shaft actuated by said mechanism, worm-gearing transmitting motion from said shaft, aWarp-beam spindle intermittingly turned by said gearing, a gripping device applied to said shaft, and transmitting devices, whereby said gripping device is periodically tightened to prevent overmovements of the warp-beam, substantially as hereinbefore specified.

5. rlhe combination, with the ratchet-shaft and a reciprocating part and connections transmitting motion thereto,- of a pair of jawlevers hinged together at one end and having concave portions which embrace said shaft, a fixed pivotal support at the outer end of one of the jaw-levers, and a contact-piece carried by the outer end of the other jaw-lever and coacting with said reciprocating part at the end of its effective movements, substantially as hereinbefore specified.

. GILBERT PARK.

Witnesses:

ERAsTUs JoNEs, J. WV. TEMPLE. 

